Electric switch



I I R. 16912` March' 20, 1928. J. D. HlLLlARD e ELECTRIC SWITCH inal Filed Feb. 8'. 1921 a His Atborheg.

Reissued Mar. 20, 1928. I

UNITED& STATES JOHN I). EILLIARD, OF SCHENECTADY, 'NEW YORK, ASSIGNOB TO GENEBAL COMPANY, OF SCEENECTADY, NEW YORK, A COBPORA'IION OI' NEW YORK'.

Original application filed February B, 1921, Serial Ho. &43,440. Divided and application filed November 28, 1922, Serial No. &02,703. Original No.'1,55,514, dated'Augut 25, 1925. Application tor ein filed August 12, 1926. Serial No. 128,883.- v

My invention` relates to electric switches and especially to switches of the type wherein a circuit is broken by the separation of contacts or electrodes immersed in aninsu lating or arc-extinguishing fluid.

When opening high power circuits under oil, the arc for'med upon separation of the switch Contacts causes a certain amount of the oil to be disassociated or volatilized thereby producin within the body of the oil a quantity of hig ly heated gas, the generation of which may createa pressure su'ficient to eject oil from the tank or even to injure' the tank itself; The oil ejected from the tank is in a more or less atomized condition and isoften carbonized so that it `forms a black deposit on objects with which it comes into contact. The oil is ejected by highly heated gas which, u on contact 'with the air, may cause secon ary explosions of suflicient violence to burst the oil tank or tear it from its sup orts. Even where the direct injury from t e ex losion is slight, the fire risk is increased, an it has frequently happened that such explosions gas with the air are prevented. To accom-.

plish this result, I inter ose *in the path of the fluid set in motion y the are a means which will revent the ejection of liquid from the tani, will separate a large part ..of the oil vapor and atomized oil from' the gas, and* will cool thefluids ejected from the i tank to a temperature below that at which they spdntaneously ignite upon contact with the air. 'These results are roduced by caus-` ing the moving liquid to e broken up into a. plurality of fine streams which are caused to flow by circuitous passa esthrough a cooling material. I prefera ly arrange these passages to communicate with the up er art of the chamber within 'which the crcut is sulatin brokenso that the liquid, put into motion by the pressure resulting from the gases formed by the arcs is thrown 'toward the'top of the chamber into' these passage-ways where its flow is impeded to cool it and se arate it from the intermingled gases. hile the specific means used to break up the movi fluds may assume a variety of forms,

FATI-:N OFFICE."

prefer to use a material having a high dielectrc strength such as quartz gravel which may vary considerably in size, pebbles from to inch being satisfactory in many cases.

My present inventionhas for its purpose the provision of means by which the perfo rated barrier described above may be utilzed n connection with a fluid break switch of the well -known explosion chamber or oil y blast type. My present invention also has for ts purpose the provision of means for qu ckly relieving the pressure within the pressure chamber of the switch.` My inventon will be better understood from the followng description taken in connection with the accompany' g drawin its scope being ponted out in the appened claims.

'Referring now to the drawing there is llustrated in the 'single fi ure thereof a tank 1 containing an; insu ating liquid 2 wthn which s immersed an explosion chami ber casing 3 formed of steel or other suitable material and arranged to be sup orted from the top (not shown) of the ta 1 by the stationary contact or electrode 4: and the insulator 5 which is shown as partially bro-j ken away. The explosion chamber' casing 3 is provided with openings 6 at its upper end within which are adapted to be seated valve heads 7 carried upon stems 8 arranged to' slide within the recesses 9 'fol-med in the circular plate 10. Springs 11 are interposed between the valve heads 7 and the plate 10 for maintaining the valves in closed position. The plate 10 and the incasing 13 together form a receptacle w ich surrounds the top and' sides of the explosion chamber 3 'but does not envelop the bottom thereof.- The plate 10 is provided with screw threads around its periphery which engage threads 12' formed in a metallc ring 12 mounted in the insulat- -ing casing 13. The plate 10 forms a tight joint between the casngs 3 and 13. Small bleed holes 14 and 23 are provided for the purpose -of permitting the oil to assume its normal level within the explosion chamber and the annular chamber formed around it by the casing 13:,

Between the casings- 3 and' 13 is arran ed a barrier l'composed ofgravel or ot er suitable material and held in place by'perfo.-

- above the` top material 22. a

rated rings 16 and 17 which aremantained tween the casngs 3 and 13; When the elec ber is' trodes 4 and 21 are separatedto break the' circuit anyare `forned between them Will volatilze or dissociate a part ofthe ambient insulating fluid thereby creating gase's which produce pressurewithin the explosion chamber. The pressure so produced is effective in interrupting the arc by reason ofthe fact that itblows a. blast ofinsulatin liquid directly across the path of the arc rawn" between parte& and 21, thereby cooling and extinguishin the same.

.The resul-e. within t e explosion cha'm- 'ited` b l the valves which`.open. at a predetermnepressure and pernt the;

. as and vapor to escape into the chambereath the lato-10 'which may contain;

*above the lower edge ofthe open ng 14 an amount of air 'suflicient to* form a, cushion for the -escaping as whereby damage to the apparatus b- .t e force of the 'exp osion s prevented e pressure created within 5 .an outlet at one end thereo s space causes the vapor' and gas to be forced downwardly throu h the gravel bar rier 15 where'they are coo ed andeondensed and from whence they escape 'to' thesurface;

of the liquid 2 in' the outer tank 1, a

[My invention .may be embodied'irother forms than that shown and described and the scope of my i'nvention.-

What I claim asnew and-desire .to secure by Letters Patent of the United Statesis 1. In'a fluid switch, a receptacle having a pressure chamber within said receptacle having an outlet at the opposite end thereof, andva barrier composed of granular material between sad recep1 acle and sad chamber.

-a swtc a' ressure chamber contammg a liquid, e ectrodes arranged to form an' arc within said chamber, said chamber having at the 'opposite ends thereof a liquid outlet for discharging said liquid into the 'path'of-said arc and a. gas outlet for discharging the gas created by `said arc, and means surrounding said chamber for cooling said gas. i i i 3. In a fluid switch, a tank adapted to contain an insulating fluid, a receptacle therein 'having' an opening at one end thereof-, a second 'receptacle enclosing" said first named receptacle and having 'an opening at theopposite end 'thereofl switch Contacts within saidfirst named receptacle, and means between said' receptacles for cooling 'the' gasesformed upon the separation of said "Contacts with an insulating 4.111 a fluid switch, a receptacle having an openingat one end thereof, a second receptacle` enclosing said first name-d recep tacle and having an opening at the opposite end thereof, switch contacts within said first named I receptacle, and gravel located between said receptacles for' cooling the gases and condensing the vapor's fol-med upon the opening of, the circuit.

5. In a fluid switch, a tank adapted to` contain an `insulating. fluid, a receptacle within saidtank, said receptacle being` open at its bottom, a second receptacle within said first" named receptacle, ibeingadaptedto be submerged in 'and filled with an insulating fluid, said second receptacle 'being provided with an o ening at its top, ar'cing electrodes within said second receptacle and ;granular cooling material between said receptacles.

-6. In -a fluid switch, a tank adapted to contain -an insulating fluid, a. receptacle within said tank, said receptacle being otpen at its bottom, a -second i receptacle wi in *said first named receptacle, said second receptacle being adapted to be submerged in and filled jwith'an insulating fluid, said second receptacle being rovided with an opening 'at'its top,-`a va ve seated in saidopening and adapted to open at a predetermined pressure, a stationary electrode located `injsaid second receptacle, an electrode adapted to cooperate' with said stationary p electrodes and movable through `an opening I, thereore, intend to cover by the appended. 'claims all chan es andmodifications a +1" parent to those s led in the art and within i' in the lower part of said second receptacle and granular cooling material between said receptacles.,`

adapted to contain' an insulating liquid, a receptacle therein having a contact receivng opening, Contacts arran ed to separate' n/ the rece tacle, one of sai contacts being withdrawa le through said opening, said receptacle having gas* discharge openings- '95 said second receptacle A adapted to contain `an insulatng Iiquid, a receptacle therein, relatively movable contacts arranged to separate initially in" the receptacle, said receptacle being provided with a contact opening and with a pressure relief opening and cooling means arran ed in communication with sad pressure re ief opening.

- 9. A fluid break switch comprising a t-ank adapted to contain an insulating lquid, a pressure chamber therein having a contact receiving openn stationary and movable Contacts arrange to separate in the ressure chamber, said chamber being provi ed with means for increasing the efliciency of the switch conprising gas discharge openings, and valvesfor controlling the discharge of fluid through said openings.

10. A liquid break switch comprising a pressure chamber containing a fixed contact, a movable contact engaging the fixed contact within the chamber, said chambehaving an opening through which the movable contact is withdrawn 'and through which a blast of liquid is projected into the path of an arc and said chamber being provided with a` bleed opening and with a discharge opening for limiting the pressure in the chamber.

11. A fluid break switch comprising a pressure chamber adapted to contain an insulating liquid, and relatively movable contacts arranged to separate initially therein,

said -chamber having an outlet for discharging liquid into the path of the arc between sad contacts and means comprising a'separate outlet for the 'discharge of as formed in the .chamber by the arc for lmitin'g the pressure in said pressure chamber.

12. A fluid break switch comprising a tank adapted to contain an insulatingliquid, cooperating fixed and movable contacts, a pressure ehamber in said tank and containing the fixed contact having an opening through which the movable contact is adapted to be withdrawn, said chamber having additional openings effective to release a suflcient quantit of gas and lquid to limit the pressure pro uced in said chamber when the switch is opened.

13. A fluid break switch comprising a tank adapted to contain insulatin liquid, a pressure chanber in said tank, a xed contact and a cooperuting movable contact rod separable in said chanber, said pressure chamber having an opening in the bottom thereof through which the contact rod is adapted to be withdrawn and said chamber having a as discharge opening at the top thereof t rough which a suflicently large quantity of gas fol-med in the chamber may be quickly released to limit the pressure therein.

In witness whereof I have hereto set ny hand this 23d day of July, 1926.

JOHN D. HILLIARD. 

